Rising Hope for a Carbon Sink

Rabat – Planting trees is “the most effective way to fight global warming,” according to a study released July 4. Swiss scientists tracked current global tree cover, and reported that the world has 0.9 billion hectares of land available for a trillion or more new trees. After excluding urban and agricultural lands, the scientists landed on a figure which is roughly the size of the continental US.

The 30 plus scientists found that the new trees could absorb over 200 billion tons of carbon. Humans have released roughly 300 billion tons of carbon into the atmosphere since the industrial revolution.

“Our study provides a benchmark for a global action plan, showing where new forests can be restored around the globe. Action is urgent and governments must now factor this into their national strategies to tackle climate change,” said the study’s lead scientist, Jean-Francois Bastin.

As straightforward as global reforestation may sound, in an era when Brazilian President Bolsonaro’s policies threaten to deforest vast swaths of the Amazon for profit, even a seemingly simple solution is far from so.

“It’s certainly a monumental challenge, which is exactly the scale of the problem of climate change,” said Thomas Crowther, one of the study’s co-authors. Crowther is the chief scientific advisor to the UN Trillion Trees Campaign.

The idea of forests as “carbon sinks” is not new, but the study reports a new scale of hope. It does so with unprecedented accuracy in current and future climate conditions. It is able to map where trees can be planted and how much carbon dioxide (CO2) they can absorb. Still, many scientists disagree with the study’s assertions.

Tree planting alone cannot solve climate change. Fossil fuels emissions must be cut significantly, and there is no simple fix to circumvent this reality. Crowther is quick to acknowledge this: “None of this works without emissions cuts.”

Today, climate justice’s ultimate goal is to limit global temperature rise to 1.5 degrees Celsius above pre-industrial levels. This is the basis for the Paris Agreement, a non-binding mechanism for developed countries to curb emissions, developing countries to continue their right to develop, and developed countries to assist developing countries in doing so on a low-carbon path.

Plants breathe in CO2, so reforestation is a basic step in combating climate change. But no amount of trees can absorb everything humans are spewing into the Earth’s atmosphere. “Yes, heroic reforestation can help,” said Myles Allen of Oxford University. “But it is time to stop suggesting there is a ‘nature-based solution’ to ongoing fossil fuel use. There isn’t. Sorry.”

Is it really a solution?

Trees cannot replace emissions cuts. But that is not the only problem other scientists have spotted with the study’s findings.

Some researchers pointed out that today’s grasslands, that will host tomorrow’s forests, are undervalued. Grasslands do not face vulnerability to forest fires, which increases as global temperatures rise and rainfall patterns shift. Grasslands might absorb less heat than trees, due to their lighter color. Some studies have shown that planting large numbers of trees in savannahs can decrease river levels and even dry streams.

“The authors have forgotten the carbon that’s already stored in the vegetation and soil of degraded land that their new forests would replace,” argued two professors from University College London. This means carbon released during reforestation must be deducted from the study’s absorption figure, and the amount is not negligible.

The same researchers argued that the study’s estimated carbon capture capacity is faulty as it assumes forests will only take a few decades to reach maturity. In reality, according to the Intergovernmental Panel on Climate Change, such maturity could take centuries longer.

The study presents another drawback at the human level. Promising a cheap and easy solution to climate change may lead to “mitigation deterrence,” according to Professor Duncan McLaren of Lancaster University. He explains that promising such an easy future solution makes it “less likely that time and money will be invested in reducing emissions now.” McLaren warns that over-celebrating such a study could harm momentum in the climate justice movement.

Urgency is, after all, pushing a global focus on climate change after decades of sidelining the topic.

Pilot programs in Morocco and Lebanon

The study’s findings are not bulletproof. But they do make some recommendations that few could argue against. The study points out goal and approach inconsistencies in different global reforestation projects. It also cautions that “better country-level forest accounting is critical for developing effective forest management and restoration strategies,” according to a news release that accompanied the study’s publication.

Morocco and Lebanon will host pilot programs in reforestation and land management. An initiative from the Union for the Mediterranean and the UN Food and Agriculture Organization will focus on these two Mediterranean countries because they are regional biodiversity hotspots. Programs will focus on Morocco’s Maamora Forest near Rabat and Lebanon’s Chouf and Bkassine Regions.

The “Scaling up forest and landscape restoration to restore biodiversity and promote joint mitigation and adaptation approaches in the Mediterranean” project was announced during the 6th annual Mediterranean Forest Week summit, hosted this April in Lebanon.

Consistency, as urged by the Swiss study, is a key benefit in the new program, according to Chadi Mohanna, the director of rural development and natural resources in Lebanon’s Ministry of Agriculture. Mohanna praised the UN Food and Agriculture Organization’s focus on bringing together national stakeholders to standardize and harmonize restoration efforts. The four-year $2 million program will include this focus at both national and regional levels.

Regardless of criticism against the Swiss study’s highly optimistic prognosis, reforestation is a likely move in these warm Mediterranean countries. The project will help the two countries meet National Determined Contributions submitted for the Paris Agreement, according to Miguel Garcia-Herraiz Roobaert, Union for the Mediterranean deputy secretary general for environment and water.

The Swiss study’s basic argument insists that carefully managed reforestation is a powerful tool to combat climate change. The projects in Morocco and Lebanon may shed further light on the study’s findings. More importantly, they will take part in “the global and political will to fight for our world” that a World Wide Fund for Nature Forestry Lead emphasized in reaction to the new report.